I have had some issues with my PM4 losing connection to my pulse belt the last few days. It would drop, not showing anything, then suddenly displaying correct pulse, back and forth. I figured it might be the battery going flat, and used my wife's belt for the rest of the rowing. But, this had the samme issue. Both are fairly old, so I guess both can have bad batteries. So, today I installed a brand new battery, and I had no issue with loosing connection. I did however had suddnly large spikes in my puls. I did 1mil steady, and suddnenly my pulse would go from 160 to 172 or 175, then climbe down to 60 again. This always happen very suddenly I dont go 162,165, 168 etc, it just climbs to 175 in a second

So, i got my pulse clock after rowing, and connected that also. It gave the same reading as my belt. I gave it a good go, and I ended up with 228 as my max pulse. Not bad for a 40 year old body

So, I'm having a heart condition without knowing it, and without any symptoms, or my belt are having issues. The only thing I can think if, is that I have a wifi access point about 1 meter away when I'm roing. Could this cause any issues?

Any other things I should be on the lookout for? Never had issues before, but something is clearly wrong.

If the wifi signal is on 2.4 ghz, it is very likely Interfering with the 2.4 gig ANT+ signal from chest belt. How about the fabric of your jersey or tee shirt? Synthetics are alleged to interfere with wireless signal?

There are two types of people in this world: Those who can extrapolate from incomplete data

I got to admit to im not wearing much when rowing, got my own machine so I can row wearing just shorts. I was sweeting good, but aside from that Wifi is the only thing I can think off, sitting right next the wireless transmitter. I will try moving it and see if it helps. I checked some more and both do transmitt over the 2,4ghz band